U.S. Army Survival Manual has 285 pages of survival tips covering; health & first aid, navigation, water, food, shelter, fire making, cooking, cold weather and jungle survival, and more. Better to have it and not need it than need it and not have it.
Actually, you’d be better off getting the FM 03-05.70
It is better to download and print by yourself than buy one of those imitation 21-76 that they sell everywhere.